The invention relates to a device for thermostatic valves that is disposed in the heating agent feed line to a radiator and, more particularly, where such a device is provided with a further, externally controlled valve for the purpose of temperature reduction at the radiator.
In typical space heating systems, it is expedient and desirable to temporarily reduce the room temperature controlled by a thermostatic valve without having to actuate the thermostatic valve. For this purpose, it has been known to equip thermostatic valves with heating resistors that can be switched on by a switch clock and which simulate a higher room temperature to the thermostats of the valves so that said valves allow a smaller quantity of heating agent, i.e. thermal energy, to be passed on through the radiator. However, the operation of a heating resistor control in such a thermostatic valve retrogrades with dropping room temperature given a constant heating resistor power, so it is necessary to increase the power applied to the heating resistor over time via a separate temperature sensor. Thus, this device has the disadvantages of being costly in technical outlay and that the heating system and thermostatic valve operation function with a delay.
Another device for temperature reduction of thermostat-controlled radiators utilizes a second, electro-thermally actuatable valve disposed in the feed line to the radiator, such as disclosed in German Offlegungschrift No. 27 27 821. The switching of this second thermal valve is controlled by means of a switch clock or from heat sensors, whereby the main thermostatic valve is left at its set temperature. This device has the disadvantage that, given a drop in the room temperature, the thermostatic valve can open wider and it is then necessary to oppose an increased flow of heating agent to the radiator with the second thermally controlled valve that acts as a choke.
An object of the present invention is to eliminate these known disadvantages and to create a device for thermostatic valves that enables a low-hysteresis regulation for the heating agent feed to a radiator and is simple in structure.